Manually decrease fan speed??? Out of warranty!

First post here. I purchased a mid 2007 20" iMac 2.0 ghz used recently. I just got it to add to our mac collection at the house. When I received it I found that the fan was always running. After installing iStat Pro I found that the optical disk drive fan was always running at about 5600 RPMs!!! This is immediately upon start up with no load.

All temperatures are normal and the CPU is 97% idle. After some research here and on the web, it looks like possibly the logic board needs replaced or something of that nature.

My question is this. I have found programs to up fan speed, but none to manually make them slower. I can return the computer to the owner, but if I can manually manage to slower the speed I may keep it for the right money. I don't often use the ODD, but when I do I could always up the speed.

I need to figure out what to do by today, so any thoughts would be greatly appreciated. Oh, and Apple's warranty ran out at the end of October 2008. WHat have you guys done when you're out of warranty and this happens?

I don't believe there is a proper way to do this. I know that smcFanControl lets you increase the fan speed, but I do not believe it will allow you to go lower than Apple's minimum. If the fans are going that quickly, I suggest you take it back. It sounds like a problem.

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